Core Replacement System

ABSTRACT

A core replacement system for a dispenser of rolled sheet material, having a core for supporting said rolled sheet material and a part insertable in the core, wherein the core is complementary to and engagable with the part such that it rotates with the core. The core is preferably made of extruded plastic, although injection molded plastic, metal or would also work. The core replacement system enables manufacturers to control which types or brands of paper are used with specified dispensers.

RELATED APPLICATION

This application claims priority from U.S. provisional application No. 60/594,360 filed on Mar. 31, 2005 and which is incorporated herein by reference in its entirety and for all teachings, disclosures and purposes.

FIELD OF THE INVENTION

This invention relates to rolls of sheet material, such as toilet paper and paper towels.

BACKGROUND OF THE INVENTION

Many manufacturers and vendors of toilet paper and paper towels provide, sell or lease dispensers to customers at subsidized rates in the expectation that those customers will purchase paper for the dispenser from that manufacturer. In this way, the customer saves on the initial cost or investment in the dispensers and the manufacturer is able to recoup money spent on the dispensers in the form of profit from the sale of toiler paper and/or paper towel.

Unfortunately, the temptation for customers is to accept the subsidized dispenser and then purchase toilet paper and/or paper towels from whoever offers the lowest price. Customers often buy “specials” on paper and use it in substitution for the specified paper, which is often slightly higher in price; this technique is known as “stuffing”.

Although efforts have been made in the prior art to develop dispenser systems that address this problem, no satisfactory solution has yet been found. Furthermore, in developing countries where the cost of labour is relatively low, it is often more economical for customers to pay employees to laboriously circumvent such dispenser systems than to purchase paper from the manufacturer or vendor that provided the dispenser in the first place.

Such substitution results in a financial loss to the paper manufacturer. Furthermore, use of inferior grade paper may cause degraded performance and result in a request for a greater number of service calls and a greater rate of deterioration of the dispenser.

Accordingly, paper manufacturers have an interest in exercising control over the type of paper that is used in its dispensers. Manufacturers have tried to prevent stuffing by modifying standard cardboard cores, e.g. by using proprietary core diameters, core widths, notched cores, or a combination thereof. Unfortunately, these techniques have proven to be ineffective.

SUMMARY OF THE INVENTION

According to one aspect of the invention there is provided a core replacement system for a dispenser of rolled sheet material comprising a core and a core interface. The core has a body around which can be rolled a sheet material and a keyway extending into the body. The core interface is mountable to the dispenser and has an extending key with a cross-section complementary to and engagable with the keyway. At least part of the keyway and at least part of the key can have non-cylindrical cross-sections. The core is preferably made of extruded plastic, although injection molded plastic, metal or wood would also work. The core replacement system enables manufacturers to control the types or brands of rolled sheet material that are used with specified dispensers.

The interface can comprise a plate for mounting to the dispenser and a rotatable part rotatably mounted to the plate and comprising the key. Alternatively, the interface can be molded directly into the dispenser. The rotatable part has a rotational axis and the key can extend parallel to and off the rotatable part axis. The keyway can be located in a position on the body such that the core rotates about the centreline of the body when the core is mounted to the core interface. The key can have a distal end with a pointed portion facing the axis of the rotatable part.

At least part of the key and at least part of the keyway can have a circular sector cross section. More particularly, at least part of the key and at least part of the keyway can have a semi-circular cross section. Alternatively, the core body can have four keyways each having a quarter-circular cross section. In another alternative, at least part of the key and at least part of the keyway can have a simple polygonal cross-section.

According to another aspect of the invention, there is provided a rolled sheet dispenser comprising a housing and a core interface mounted to the housing. The core interface has an extending key with a cross-section complementary to and engagable with a keyway in a core. The core has a body around which can be rolled a sheet material and the keyway extends into the body.

According to yet another aspect of the invention, there is provided a method of manufacturing a core replacement system comprising:

-   -   (a) manufacturing a core having a body around which can be         rolled a sheet material and a keyway extending into the body by         a method selected from the group consisting of injection         molding, extrusion, and machining; and     -   (b) manufacturing a core interface comprising a plate mountable         to a dispenser and a rotatable portion rotatably mountable to         the plate and having an extending key with a cross-section         complementary to and engagable with the keyway, by a method         selected from the group consisting of injection molding,         extrusion and machining.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention itself both as to organization and method of operation, as well as additional objects and advantages thereof, will become readily apparent from the following detailed description when read in connection with the accompanying drawings wherein:

FIG. 1 is a perspective view of a core according to one embodiment of the present invention;

FIG. 2 is a transparent perspective view of the core shown in FIG. 1;

FIG. 3 is a perspective view of a roll of paper wound around the core;

FIG. 4 is an exploded perspective view of a core interface comprising a rotating part and a plate according to an embodiment of the present invention;

FIG. 5 is a perspective view of the core interface wherein the rotating part and plate are assembled together;

FIG. 6 is a perspective view of the core interface engaging the core shown in FIG. 1;

FIG. 7 is a cutaway perspective view of the core interface engaged with the core shown in FIG. 1;

FIG. 8 is a cutaway according to an embodiment view of the core interface engaged with a prior art core; and

FIG. 9 show multiple cross-sectional views of a number of alternative core embodiments.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Rather than a standard cardboard core and bung known in the prior art, a core system 5 as shown in FIGS. 1-7 and 9 is provided for use in a rolled sheet dispenser (not shown) in accordance with one embodiment of the invention. The system 5 comprises a core 10 and a rotatable dispenser interface 15. The core 10 is a cylindrical body over which a paper roll A is wound. The dispenser interface 15 is mounted to the dispenser and rotatably engages the core 10 such that the paper roll A can be rotated within the dispenser. In a first embodiment as shown in FIGS. 1 to 3, the core 10 has a hollow cylindrical portion divided into four longitudinally extending segments 40 by a pair of longitudinally-extending planar portions intersecting inside the cylindrical portion to form a “X” shaped cross section. Each segment 40 serves as a keyway that can engage a complementary key portion of the interface 15. While the core 10 shown FIGS. 1 to 3 has four segments 40 each being a quarter circular sector in cross-section, it is within the scope of the invention for the core 10 to comprise a different number and/or shapes of segments 40; see for example, the alternative embodiments of the core shown in FIG. 9.

The core 10 preferably made of extruded plastic. However, the core 10 can also be made from injection molded plastic, metal or wood, and can be manufactured by injection molding, extrusion, or machining. The core 10 can also be made of cardboard at least for some of the embodiments of the core shown in FIGS. 1 to 3, and 9.

The present system 5 requires a paper manufacturer to use the core 10 as the paper is being manufactured into rolls A. Referring to FIGS. 4 and 5, the interface 15 is mounted on the dispenser and comprises an annular plate 20 and a rotating part 30. The plate 20 is attached to the dispenser, e.g. by snapping into place, or integrally molded into the dispenser. The rotating part 30 has a circular portion that snaps into the center of the plate 20 in a way that will allow the rotating part 30 to rotate freely relative to the annular plate 20. The rotating part 30 also comprises a key that extends longitudinally outwards from the circular portion. Referring to FIGS. 6 and 7, the key is shaped to fit into one of the segments 40 of the core 10, and in particular has a longitudinally-extending and curved surface corresponding to the curvature of the core segment 40 and a distal end having a circular sector cross section corresponding to the cross sectional shape of the core segment 40. The distal end has a sharp point 50 pointing radially inwards towards the rotational axis of the rotating part 30. The rotating part 30 key and the core 10 keyway fit such that the roll A is supported properly and can rotate freely within the dispenser.

Referring to FIG. 8, a dispenser equipped with the core system 5 will prevent non-compatible rolls from working properly with the dispenser, thereby dissuading the owner of the dispenser from purchasing generic rolls. If a generic roll B having a conventional hollow cylindrical cardboard core is placed in a dispenser equipped with the core system 5, the generic roll will not be supported properly and will tend to fall off. Also, the sharp point 50 of the key will tend to dig into the cardboard of the generic paper roll, thereby impeding the paper roll from rotating properly.

Some other possible cross-sections that could be used for the core 10 are shown in FIG. 9. A corresponding number and configurations of parts 30, having shapes corresponding to the cross-sectional shapes of the segments 50 shown in FIG. 9 will be readily apparent to persons skilled in the art.

Accordingly, while this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to this description. It is therefore contemplated that the appended claims with cover any such modifications or embodiments as fall within the scope of the claims. 

1. A core replacement system for a dispenser of rolled sheet material, comprising: (a) a core having a body around which can be rolled a sheet material and a keyway extending into the body; and (b) a core interface mountable to the dispenser and having an extending key with a cross-section complementary to and engagable with the keyway.
 2. A core replacement system as claimed in claim 1 wherein at least part of the keyway and at least part of the key have non-cylindrical cross-sections.
 3. A core replacement system as claimed in claim 2 wherein the interface comprises a plate for mounting to the dispenser and a rotatable part rotatably mounted to the plate and comprising the key.
 4. A core replacement system as claimed in claim 3 wherein the rotatable part has a rotational axis and the key extends parallel to and off the rotatable part axis.
 5. A core replacement system as claimed in claim 4 wherein the keyway is located on the body such that the core rotates about the centreline of the body when the core is mounted to the core interface.
 6. A core replacement system as claimed in claim 4 wherein the key has a distal end with a pointed portion facing the rotatable part axis.
 7. A core replacement system as claimed in claim 2 wherein at least part of the key and at least part of the keyway have a circular sector cross section.
 8. A core replacement system as claimed in claim 7 wherein at least part of the key and at least part of the keyway have a semi-circular cross section.
 9. A core replacement system as claimed in claim 7 wherein the core body has four keyways each having a quarter-circular cross section.
 10. A core replacement system as claimed in claim 2 wherein at least part of the key and at least part of the keyway have a simple polygonal cross-section.
 11. A rolled sheet dispenser comprising: a housing and a core interface mounted to the housing and having an extending key with a cross-section complementary to and engagable with a keyway in a core, the core having a body around which can be rolled a sheet material and the keyway extending into the body.
 12. A rolled sheet dispenser as claimed in claim 11 wherein at least part of the keyway and at least part of the key have non-cylindrical cross-sections.
 13. A rolled sheet dispenser as claimed in claim 12 wherein the interface comprises a rotatable part rotatably mounted to the housing and comprising the key.
 14. A rolled sheet dispenser as claimed in claim 13 wherein the rotatable part has a rotational axis and the key extends parallel to and off the rotatable part axis.
 15. A rolled sheet dispenser as claimed in claim 14 wherein the keyway is located on the body such that the core rotates about the centreline of the body when the core is mounted to the core interface.
 16. A rolled sheet dispenser as claimed in claim 14 wherein the key has a distal end with a pointed portion facing the rotatable part axis.
 17. A rolled sheet dispenser as claimed in claim 12 wherein at least part of the key and at least part of the keyway have a circular sector cross section.
 18. A rolled sheet dispenser as claimed in claim 17 wherein at least part of the key and at least part of the keyway have a semi-circular cross section.
 19. A rolled sheet dispenser as claimed in claim 12 wherein at least part of the key and at least part of the keyway have a simple polygonal cross-section.
 20. A method of manufacturing a core replacement system comprising: (a) manufacturing a core having a body around which can be rolled a sheet material and a keyway extending into the body by a method selected from the group consisting of injection molding, extrusion, and machining; and (b) manufacturing a core interface comprising a plate mountable to a dispenser and a rotatable portion rotatably mountable to the plate and having an extending key with a cross-section complementary to and engagable with the keyway, by a method selected from the group consisting of injection molding, extrusion and machining. 